Overview of the Issue
When using Advanced Custom Fields with Repeater fields in a multilingual setup, reordering the repeater fields in the default language causes the translations to become unsynchronized.
Workaround
This issue is fixed. Updating to the latest version solves it on your site, so you only need this workaround if you can’t update yet.
Our developers are aware of this situation. In the meantime, you can make a small change to the default language post. This will invalidate the current translation job and will force WPML to re-create a new one with the right Repeater fields order.